Category Archives: science

A Positive Sign

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I’m always pleased to see this sign. It is at Heathrow, on the walk down the perpetually dingily lit underground corridors connecting the terminals, the tube, the extortion Heathrow express, and the parking lots.

For a start, I generally like the idea that the ground floor of a building (the one you walk onto off the street) is the “zeroth” floor. (I mean no disrespect to this splendid country I live in, that has largely chosen otherwise, although every now and again in older buildings you see it.) So it is just great to see […] Click to continue reading this post →

News From the Front, IV

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So imagine the following:

You’re walking along the street, minding your own business, and somebody walks up to you and tries to sell you a string theory. So you stop and examine the goods, since you’re in the market for string theories, on the lookout for any that might be novel, useful, bright, or shiny, etc. You never know when one or other property might come in useful.

Question: How do you know that it is a string theory? Let me be sure to point out that it comes with a lot of the defining path integral done for you. In other words, you don’t have to do the integral over string world sheet metrics and world sheet fields. This was done in the factory for you. What you have access to are parameters such as the coefficients of the operators in the theory, and you can also adjust the value of the string coupling.

So a lot of the stuff you would recognize as a string theory in your typical string theorist’s notebook have been cleaned up. They’ve been integrated over. The observable physics actually never cared about them (the technical details of summing over metrics – slicing up the moduli space of inequivalent metrics properly at each genus, etc etc…. all done), assuming you’ve done the integrals properly. The factory did it all for you.

So what criteria do you use to decide that it is a string theory at all? Actually, this is not an idle question. Think about the issue in the context of trying to understand some […] Click to continue reading this post →

Finding the Orionids Tonight

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When I was a child, I was fascinated with a straight line of three stars that were evenly spaced. Whenever I looked up in the sky, I would be comforted by being able to find those stars, especially when I was about to embark on a long walk home at night. I later learned that they were actually known as Orion’s Belt, part of the constellation of Orion. So Orion remains my favourite constellation.

These nights, Orion takes centre stage in stargazing circles since the Orionid meteor shower will be originating from a point near the constellation. Of course, Orion has nothing to do with the shower. It merely marks the apparent direction that it comes from (see red dot in image below).

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(Above is the view of the sky looking Southsoutheast from mid northern latitudes at 3:00am today.) We will be traversing a debris field made of stuff left over from Halley’s comet’s tail. That stuff will rain down into our atmosphere, glowing brightly […] Click to continue reading this post →

Those Self-Fulfilling Prophecies

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You may recall that we were recently discussing stereotypes as a result of an earlier post. Particularly, I was talking about the effects those sterotypes can produce as a result of modifying the expectations of others, making it hard for some people to be taken seriously, and resulting in them having to go that extra mile (or several) as a result.

Well, I’d like to point your attention to a recent study about the direct effects of those stereotypes on the stereotyped. Quoting from an article by AP science writer Randolph E. Schmid:

[Steven J.] Heine and doctoral student Ilan Dar-Nimrod wanted to see how people are affected by stereotypes about themselves. They divided more than 220 women into four groups and administered math and reading comprehension tests between 2003 and 2006. Their results are reported in Friday’s issue of the journal Science.

What they actually did was to provide the different groups with different images and reading materials before they did the tests. They seem to have found significant differences in the results that suggest that having a negative stereotype of yourself in mind actually makes things worse. In other words:

It’s a process psychologists call a stereotype threat, Heine explained. “If a member of a group for which there is a negative stereotype is in a position to test the stereotype, they are likely to choke under the pressure.”

So reminding them of the stereotype affects them.

Here’s what they found: […] Click to continue reading this post →

The Lives Of The Stars

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Well, I’m back from the visit to the preview of the Griffith Observatory that I mentioned to you I was going to. It was a rather good visit. They organised it well, and -boy!- have they done a great job on the restorations! I’ll try and assemble the several pictures that I took into some sort of narrative for you, and report soon. While you wait, here’s one of my favourites:

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This is particularly poignant, in my opinion. The children are looking at the lovely […]
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New Colleagues

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Ah! The joy of new colleagues! I have somehow forgotten to tell you one piece of the great news that we had here at USC Physics and Astronomy recently. We got three new faculty, and one of them is here in action (I’ll tell you about the others later), telling us about the physics behind the 2006 Physics Nobel Prize. This is Cosmologist/Astrophysicist Elena Pierpaoli:

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She’s one of those people who works closely on (among other things) the data from […] Click to continue reading this post →

Brown and Nerdy

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Well, here’s an amusing response to Weird Al Yankovic’s video* (see my earlier post on the issues I had with it). He makes his point with charming clumsiness, but… he makes the point.

Still here:

[…]

…and YouTube links here, and here. (Watch them in order for maximum hilarity.)

[…] Click to continue reading this post →

Manifold Yau

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Well, here’s yet another discussion of Yau to gobble up. It is a New York Times article by Dennis Overbye on Yau, his life and work*. I’ve no idea why this was written, or what the timing was. I’d like to believe that it was just because it is a good subject -because it is- and that it is worthwhile to do an article about a Mathematician of considerable stature in the field, and about the ins and outs of the world of Mathematics -because it is. But I can’t help but wonder if this would have seen the light of day if there was not the big argument going on about the New Yorker article and Yau’s displeasure with its contents. […] Click to continue reading this post →

Happy Flipping Memories

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A couple of magazines showed up in the post the other day, unlooked for (as JRR would write). Spent a short (unfortunately) time lying on my bed in the sun flipping through them, and it reminded me of my boyhood. Do you remember something similar? You’d go out and get that next issue of that magazine you’d been waiting for and you’d just drink it all up in a general way for a while, lying on your stomach, legs kicking in the air: The smell of the pages, the glossy pictures and other juicy tidbits of writing and other stuff to digest more fully later on….

For me, when I was young it was mostly magazines about music, electronics, computers, science… some crochet, macrame, and knitting (yeah, I know – I’ll tell you more later), and of course lots of comics (these latter I did not browse first… I would read […] Click to continue reading this post →

Lighting Up Your Quantum Class

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I forgot to tell you about this last week, so here goes. The colloquium last week was given by John O’Brien. One of the perks of the job of having to organize the department’s colloquium series is that you can use it (on rare occassions) as a blunt tool to find things out. I’ve always been curious about connecting the name I saw on one of the labs downstairs to a face. John’s lab, primarily part of the Engineering department, uses a little of the space in our building, you see, but I’ve never really made the connection between the face and the name. It certainly seemed that the USC Center for Photonics, of which he is part, was certainly up to some interesting and fun stuff, and so, egged on by another curious colleague, I sent him an invitation to give us a colloquium. He generously accepted, and here he is:

The talk -see the abstract here- was excellent. As you can see from the website listing the faculty in the centre, they are concerned with all sorts of fun things to do with very small scale devices which do rather clever things with light, such as nanoscale semiconductor lasers. The reason that the talk was excellent, in my opinion, was because it was not a standard device+engineering talk that you can often get from very good engineers who nevertheless don’t neccessarily appreciate what aspects the physicists care about. Those talks can often be pretty pictures and […] Click to continue reading this post →